Description
In the PatternMatch function in fontfile/fontdir.c in libXfont through 1.5.2 and 2.x before 2.0.2, an attacker with access to an X connection can cause a buffer over-read during pattern matching of fonts, leading to information disclosure or a crash (denial of service). This occurs because '\0' characters are incorrectly skipped in situations involving ? characters.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libxfont | 1:2.0.1-4 | — |
| Debian 13 | libxfont | 1:2.0.1-4 | — |
| Debian 12 | libxfont | 1:2.0.1-4 | — |
| Debian 9 | libxfont | 1:2.0.1-3+deb9u1 | DSA-3995-1 |
| Debian 8 | libxfont | 1:1.5.1-1+deb8u1 | DSA-3995-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 7 | libxfont | 1:1.4.5-5+deb7u1 | DLA-1126-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | libxfont | 1:1.5.1-1ubuntu0.16.04.3 | USN-3442-1 |
| Ubuntu 16.04 LTS | libxfont2 | 1:2.0.1-3~ubuntu16.04.2 | USN-3442-1 |
| Ubuntu 14.04 LTS | libxfont | 1:1.4.7-1ubuntu0.3 | USN-3442-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | libXfont | 1.5.1-11.3.12 | SUSE-SU-2018:0334-1 |
| SLES 12 SP2 | libXfont | 1.5.1-11.3.12 | SUSE-SU-2018:0334-1 |
| SLES 11 SP4 | xorg-x11-libs | 7.4-8.26.50.5.3 | SUSE-SU-2018:0246-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP3 | libXfont | 1.5.1-11.3.12 | SUSE-SU-2018:0334-1 |
| SLES for SAP 12 SP2 | libXfont | 1.5.1-11.3.12 | SUSE-SU-2018:0334-1 |
| SLES for SAP 11 SP4 | xorg-x11-libs | 7.4-8.26.50.5.3 | SUSE-SU-2018:0246-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | libXfont | 1.5.4-2.18 | openSUSE-SU-2024:10921-1 |
Advisories 6
- USN-3442-1 libxfont, libxfont1, libxfont2 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-3995-1 libxfont - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1126-1 libxfont - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10921-1 libXfont-devel-1.5.4-2.18 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0334-1 Security update for libXfont SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0246-1 Security update for xorg-x11-libs SUSE / openSUSE Security Updates · Feb 4, 2026
References
- DSA-3995 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1500690
- https://bugzilla.suse.com/show_bug.cgi?id=1054285
- https://www.x.org/releases/individual/lib/libXfont2-2.0.2.tar.bz2
- GLSA-201711-08 vendor-advisory
- https://cgit.freedesktop.org/xorg/lib/libXfont/commit/?id=d1e670a4a8704b8708e493ab6155589bcd570608